<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>

    <style>
        .aaa {
            width: 500px;
            height: 400px;
            border: 3px solid red;
        }

        .aaa:hover {
            border: 3px solid gold;
        }

        .bbb img {
            width: 500px;
            display: none;
        }

        .bbb:hover img {
            display: block;
        }
    </style>
</head>
<body>
<form method="post" action="/login">
    <h1>用户登录</h1>
    <div>
        用户名：<input type="text" name="username">
    </div>
    <div>
        密 码：<input type="password" name="password">
    </div>
    <div>
        <input type="submit" value="登录">
    </div>
</form>
<div class="aaa">
    <div class="bbb">
        <button>图片</button>
        <img src="/111.jpg" alt="急急急">
    </div>


</div>
</body>
</html>